JP2019149834A - Random access method, apparatus, and communication system supporting multiple types of transmission time intervals - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a random access method, an apparatus and a communication system supporting a plurality of types of TTIs. In a random access method, a user apparatus transmits a preamble for requesting random access to a base station by a first message. Among them, the TTI type of the user device is indicated by the first message. The user device receives the random access response transmitted by the second message from the base station. Of these, different types of TTIs support different random access responses. As a result, the latency of the random access procedure of the user device of the short TTI can be significantly reduced. [Selection diagram] Fig. 1

Description

  The present invention relates to a communication technology field, and more particularly to a random access method, apparatus, and communication system that support a plurality of types of transmission time intervals (TTI) in an LTE (Long Term Evolution) system.

  Real-time traffic such as automatic operation and industrial automatic control appearing in next-generation mobile communication networks has a very high demand for transmission latency, and for example, requires peer-to-peer (P2P) latency between 1 ms and 10 ms. These traffic present a relatively large challenge to network latency performance when carried by the LTE system. Further, regarding conventional transmission control protocol (TCP) traffic, the throughput of the system can be significantly improved by reducing the peer-to-peer latency. Considering these two aspects, it is urgently necessary to reduce traffic peer-to-peer latency in LTE systems.

In ^{3GPP (3 rd Generation Partnership Project)} , a method for reducing the latency of the peer-to-peer by reducing the TTI it has been studied. The TTI adopted by the legacy user equipment (UE, User Equipment) is 1 ms, which is the same as the length of the subframe, that is, the basic time unit for scheduling data is 1 ms. If the latest released UE supports shortened TTI (also called shortened TTI), for example, if the TTI is 0.5ms or shorter, the peer-to-peer latency of traffic will be significantly reduced. There is. In the conventional system, the round trip time (RTT, Round Trip Time) is eight TTIs. After the TTI has been shortened, the RTT may change from the original 8ms to 4ms and may even be shorter.

  Therefore, in the LTE cell, a conventional UE (legacy UE) (for example, a UE employing 1 ms TTI) and a UE having a short TTI (also referred to as a short TTI UE) (shorter TTI UE. For example, more than 1 ms) There may be simultaneous UEs that employ short TTIs. The LTE system design needs to maintain backward compatibility and ensure that traditional UEs and short TTI UEs work simultaneously without affecting each other.

  The introduction of the background art described above is intended to explain the technical solution of the present invention clearly and completely and to make it easier for those skilled in the art to understand it. These schemes are described in the background section of the present invention and should not be construed as well known to those skilled in the art.

  However, the inventor discovered the following. That is, if a plurality of types of TTI user apparatuses perform random access according to a conventional protocol, the base station cannot distinguish which type of TTI user apparatus the preamble (Preamble) is transmitted. Further, since the user apparatus cannot distinguish the received random access response (RAR), it may cause ambiguity or error in RAR reception.

  Embodiments of the present invention provide a random access method, apparatus, and communication system that support a plurality of types of TTIs, in which a message in a random access procedure of a user equipment with a short TTI is shorter than a TTI of a conventional UE. Is allowed to be transmitted.

According to a first aspect of an embodiment of the present invention, a random access method supporting a plurality of types of TTIs is provided, which is used in a user equipment, and the random access method includes:
The user equipment transmits a preamble for requesting random access to the base station by a first message, wherein the TTI type of the user equipment is indicated by the first message; and the user equipment A random access response transmitted by the second message from the station is received, of which different TTI types include corresponding to the different random access responses.

According to a second aspect of an embodiment of the present invention, there is provided a random access device that supports a plurality of types of TTI, which is configured in a user device, and the random access device includes:
Random request transmission unit for transmitting a preamble for requesting random access to a base station by a first message, wherein the TTI type of the user equipment is indicated by the first message A random response receiving unit for receiving a random access response transmitted by the second message from the base station, wherein different TTI types correspond to different random access responses. .

According to a third aspect of an embodiment of the present invention, a random access method supporting a plurality of types of TTIs is provided, which is used in a base station, and the random access method includes:
A base station receives a preamble for requesting random access transmitted from a user equipment by a first message, wherein a TTI type of the user equipment is indicated by the first message; and The second message transmits a random access response to the user apparatus, and different TTI types include corresponding to the different random access responses.

According to a fourth aspect of an embodiment of the present invention, there is provided a random access device that supports a plurality of types of TTI, which is configured in a base station, and the random access device includes:
A random request receiving unit for receiving a preamble for requesting random access transmitted from a user device by a first message, wherein the TTI type of the user device is indicated by the first message, A random request receiving unit; and a random response transmitting unit for transmitting a random access response to the user apparatus by a second message, wherein different TTI types correspond to the different random access responses. including.

According to a fifth aspect of an embodiment of the present invention, there is provided a communication system, which supports multiple types of TTI, the communication system comprising:
Including user equipment and base station,
The user device transmits a preamble for requesting random access by a first message, wherein the TTI type of the user device is indicated by the first message; and the random message transmitted by the second message Receive access response,
The base station receives the preamble transmitted from the user apparatus by the first message; and transmits the random access response to the user apparatus by the second message, of which different TTI types Correspond to the different random access responses.

  According to another aspect of an embodiment of the present invention, a computer readable program is provided, of which, when executing the program in a user device, the program is transmitted to a computer as described above in the user device. Run the random access method.

  According to another aspect of an embodiment of the present invention, there is provided a storage medium storing a computer readable program, wherein the computer readable program causes a computer to execute a random access method as described above in a user device. .

  According to another aspect of an embodiment of the present invention, a computer readable program is provided, of which when executing the program in a base station, the program is transmitted to the computer as described above in the base station. Run the random access method.

  According to another aspect of an embodiment of the present invention, a storage medium storing a computer readable program is provided, wherein the computer readable program causes a computer to execute a random access method as described above in a base station. .

  The beneficial effect of the embodiment of the present invention is as follows: In other words, by indicating the TTI type of the user equipment using the first message for transmitting the preamble, the base station can determine what kind of TTI the preamble is. Can be distinguished from each other, and the user equipment can distinguish the received RAR, so that there is no ambiguity or error in RAR reception. Thereby, the latency of the random access procedure of the user apparatus with a short TTI can be significantly reduced.

  DETAILED DESCRIPTION Reference will now be made to the following description and drawings to disclose specific embodiments of the invention in detail and to illustrate aspects in which the principles of the invention can be employed. In addition, embodiment of this invention is not limited by these on the range. Within the scope of the appended claims, embodiments of the invention may include various changes, modifications, and alternatives.

  Also, the features described and / or illustrated for one embodiment may be used in one or more other embodiments in the same or similar manner, in combination with features in other embodiments, or in other implementations. Features in the form can also be replaced.

  It should be noted that terms such as “comprising / having” as used herein refer to the presence of a feature, element, step, or assembly, but one or more other features, elements, steps, Or it does not exclude the presence or addition of assemblies.

  Many aspects of the invention can be better understood with reference to the following drawings. It should be noted that the elements in the drawings are not drawn to scale, but merely to illustrate the principles of the invention. In addition, in order to describe and exemplify a part of the present invention, a corresponding part in the drawings may be enlarged or reduced.

Also, elements and features described in one drawing or implementation of the invention may be combined with elements and features shown in one or more other drawings or implementations. Moreover, in the drawings, like numerals indicate corresponding elements in the several drawings, and can also be used to indicate corresponding elements used in multiple implementations.
FIG. 5 is a diagram illustrating a random access method that supports a plurality of types of TTIs according to the first embodiment of the present invention. FIG. 10 is another diagram showing a random access method supporting a plurality of types of TTIs in the first embodiment of the present invention. FIG. 3 is a diagram illustrating a preamble having a length different from that of the conventional one in the first embodiment of the present invention. FIG. 3 is a diagram illustrating a preamble having the same length as in the conventional example in the first embodiment of the present invention. It is a figure which shows grouping of 64 sequences which UE of short TTI in Example 1 of this invention occupies. It is a figure which shows the random access method which supports multiple types of TTI in Example 2 of this invention. FIG. 10 is a diagram illustrating a random access device that supports a plurality of types of TTIs according to Example 3 of the present invention. FIG. 10 is another diagram showing a random access device that supports a plurality of types of TTIs in Embodiment 3 of the present invention. FIG. 6 is a diagram showing a user apparatus in Embodiment 3 of the present invention. FIG. 10 is a diagram showing a random access device that supports a plurality of types of TTIs in Example 4 of the present invention. FIG. 10 is another diagram showing a random access device that supports a plurality of types of TTIs in Example 4 of the present invention. FIG. 10 is a diagram showing a base station in Example 4 of the present invention. FIG. 10 is a diagram showing a communication system in Example 5 of the present invention.

  The foregoing and other features of the present invention will become apparent upon reference to the accompanying drawings and the following description. It should be noted that although the specification and drawings disclose specific implementation modes of the present invention, they show only a part of the implementation modes in which the principle of the present invention can be adopted. It is not limited to the implementations described, that is, the invention includes all modifications, variations and alternatives within the scope of the appended claims.

  The LTE random access procedure (explained by contention based random access as an example) is mainly directed to the base station (e.g., eNB) in four steps, i.e., the UE transmits a preamble with message 1. Initiate random access procedure; base station provides RAR with message 2 to provide timing synchronization and uplink resource grant (UL Grant) for the UE; UE sends message 3 to the base station ID (identification) is provided for performing contention resolution with other UEs; and the base station notifies the UE of successful access by message 4.

  In the random access procedure, transmission of RAR is started from three TTIs after message 1, and message 3 is transmitted from six TTIs after receiving RAR. In consideration of the latency angle, if a UE with a short TTI employs a shortened TTI for transmission in the above four messages during the random access procedure, the latency of the random access procedure may be significantly reduced.

  Taking a UE in a connected state with lost synchronization as an example, the downlink and uplink latencies of the conventional random access procedure are 13.5 ms and 10.5 ms, respectively. If a random access procedure can be transmitted with a TTI of 0.5 ms, the latency of the procedure can be reduced to approximately half of the original value, ie 6.5 ms and 5 ms. This is important for reducing latency when a UE whose synchronization has been lost transmits uplink or downlink data. Therefore, in the random access procedure, UEs that support multiple types of TTI need to access the network at the same time and ensure compatibility.

  All UEs in the cell already know the TTI type supported by the base station from the system information of cell broadcast (broadcast), and UEs with short TTIs are already working under one type of short TTI mode Suppose you choose to do. The random access procedure that occurred at this time may be from a conventional UE, and there may be short TTI UEs (multiple types of short TTI UEs may exist, for example, TTI is 0.5 ms , 0.14ms, etc.).

  However, according to the UE behavior defined in the conventional protocol, the random access channel resources and the available preamble sequences used by the preamble transmitted by the UE in message 1 are all for the base station for all UEs. It is a unified structure. The base station detects a preamble sequence that can appear on the configured resource position, and performs different RARs based on the time-frequency resource position and sequence characteristics where the detected preamble is located. However, for now, these resources and sequences are both defined for conventional UEs. The base station cannot distinguish which type of TTI UE the detected preamble is from.

  Further, after transmitting the message 1, the UE can receive the RAR that can be reached within one reception window. However, if the random access time frequency resource position and the preamble sequence selected by the conventional UE and the short TTI UE are the same, the RAR scrambling sequence, that is, the random access radio network temporary identifier (RA-RNTI) and its flag The RAPID field is exactly the same. If a certain UE cannot distinguish whether the received RAR is a conventional UE or one transmitted to a short TTI UE, it may cause ambiguity and error in RAR reception.

  Therefore, it is necessary to design a unique method for random access procedures to support multiple types of TTI UEs, mainly a method of distinguishing UE TTI types by preamble, and UEs of different TTI types. Including a method for distinguishing RARs sent to.

  In the present invention, on the one hand, the type of UE that causes random access to the base station, in order to be able to transmit under short TTI mode corresponding to the short TTI UE when the base station transmits RAR. Can be notified as soon as possible. In other words, by carrying the UE's TTI type information in the message 1, the base station can distinguish which type of UE the preamble is transmitted. On the other hand, the base station may send different types of RAR messages to different types of UEs and ensure that the corresponding UEs can receive the corresponding RAR correctly.

  Hereinafter, although the present invention will be described by taking random access based on contention as an example, the present invention is not limited to this, and can be applied to, for example, a non-contention random access procedure.

  Embodiments of the present invention provide a random access method that supports multiple types of TTI, which is used for user equipment.

  FIG. 1 is a diagram illustrating a random access method that supports a plurality of types of TTIs according to an embodiment of the present invention, and illustrates a situation on a user apparatus side. As shown in FIG. 1, the random access method includes the following steps.

Step 101: A user equipment transmits a preamble for requesting random access to a base station by a first message, and indicates the TTI type of the user equipment by the first message;
Step 102: The user equipment receives the RAR transmitted by the second message from the base station, among which different TTI types correspond to different RARs.

  FIG. 2 is another diagram illustrating a random access method that supports a plurality of types of TTIs according to an embodiment of the present invention. When a random access procedure based on contention is adopted, user devices and base stations alternate (exchange). Shows the situation. As shown in FIG. 2, the random access method includes the following steps.

Step 201: The user equipment transmits a preamble for requesting random access to the base station by a first message, and indicates the TTI type of the user equipment by the first message;
Step 202: The base station transmits RAR to the user equipment by a second message, among which different TTI types correspond to different RARs.

  As shown in FIG. 2, as an option, the random access method may further include the following steps.

Step 203: the user equipment sends a user equipment identifier (ID) to the base station in a third message for conflict resolution;
Step 204: The base station transmits contention result information to the user equipment by a fourth message.

  In the present embodiment, the user device includes a first user device that uses the first TTI type and a second user device that uses the second TTI type, and includes the first TTI type and the second TTI type. The corresponding TTI is different and is less than 1 ms.

  Among them, the first user device may be one or more types of user devices that use the first TTI type, and the second user device may be one or more ones that use the second TTI type. It may be a type of user device. The base station unifies the resources for a certain type of user equipment.

  Hereinafter, the first user device is a user device with a TTI of 1 ms (ie, a conventional UE), and the second user device is a user device with a TTI (eg, 0.5 ms) smaller than 1 ms (ie, a UE with a short TTI). This will be described as an example. Among them, there may be multiple types of short TTI UEs.

  When the user equipment starts random access, it transmits one preamble as a first message (message 1) on one available resource, and the base station transmits the preamble on time frequency resources of all preambles. Detect and receive. The TTI type of the user apparatus can be distinguished by resources used by the preamble, and can also be distinguished by the format or contents of the preamble.

  In one implementation scheme (that is, implementation scheme 1.1), multiple types of TTIs may be distinguished according to the resources occupied by the preamble. The resource may include one or any combination of a time domain resource, a frequency domain resource, and a sequence resource.

  Specifically, the UE selects an available time domain resource configured by the base station, an available frequency domain resource, and selectable ZC (Zadoff-Chu) sequences (64 in total), Send the preamble. Thus, the following three methods can be used to distinguish the preambles of different TTI type UEs, ie, allocating exclusive time domain resources for short TTI UEs; for short TTI UEs Allocate exclusive frequency domain resources to; allocate exclusive ZC sequences for short TTI UEs. Any one of these three methods may be used, or a plurality of methods may be used in combination.

<Method 1.1.1>
The time domain resource for transmitting the preamble from the first user apparatus and the time domain resource for transmitting the preamble from the second user apparatus are different and orthogonal to each other.

  For example, the first user device uses a first time domain resource table, and the second user device uses a second time domain resource table. In the first time domain resource table and the second time domain resource table, the same physical random access channel (PRACH, Physical Random Access Channel) configuration index (Configuration Index) corresponds to different subframe order numbers (subframe numbers). To do.

  Specifically, the conventional UE determines the available subframe sequence numbers in Table 5.7.1-2 in the TS 36.211 protocol based on the parameter prach-ConfigIndex configured by the base station, that is, the time domain resource. Look up.

Table 1 is a time domain resource table (same as Table 5.7.1-2 of TS 36.211) used by a conventional UE.

  In order to distinguish from a conventional UE, a time domain resource (ie, subframe order number) used by a short TTI UE is mutually different from a time domain resource that can be used by the corresponding conventional UE under the same prach-ConfigIndex. Should be orthogonal. In other words, the base station configures the same prach-ConfigIndex for all UEs, but the set of usable subframe order numbers indicated by conventional UEs and short TTI UEs are quite different (ie, common No set).

  One implementation may define one new time domain resource table, which corresponds in parallel with Table 5.7.1-2 in the TS 36.211 protocol, for example, as shown in Table 2. A short TTI UE performs a lookup only in Table 2 when selecting a time domain resource to transmit the preamble. Note that the specific contents of the table are not limited to those in Table 2, as long as the conditions orthogonal to the conventional UE lookup table can be satisfied. Similarly, the implementation method is not limited to the method of constructing a unique time domain resource table, and the time domain resource selected by the short TTI UE and the time domain resource selected by the conventional UE are orthogonal to each other. Any method that can be made is within the scope of the present invention.

Table 2 is a time domain resource table (newly defined in the present invention) used by the short TTI UE.

  Note that Table 2 shows only the case where the present invention employs time domain resources to distinguish preambles, but the present invention is not limited to this. For example, the specific contents of Table 2 are appropriately described. You may adjust it.

<Method 1.1.2>
The frequency domain resource from which the first user apparatus transmits the preamble and the frequency domain resource from which the second user apparatus transmits the preamble are different and orthogonal to each other.

  For example, the first user apparatus selects a frequency domain resource for transmitting the preamble using a first parameter, and the second user apparatus transmits a frequency domain resource for transmitting the preamble using a second parameter. Select.

  Specifically, the conventional UE selects a frequency domain resource for transmitting a preamble based on a parameter prach-FreqOffset (first parameter) configured by the base station. If the system bandwidth is greater than 1.4 MHz, new frequency domain resources can be added for short TTI UEs, which are orthogonal to the frequency domain resources used by conventional UEs.

  The base station adds a new parameter prach-FreqOffset-shorterTTI (second parameter) in the parameter PRACH-Config to indicate the frequency region used by the UE with the short TTI, and the parameter range is, for example, 0 to 94 It is. The conventional UE may ignore the parameter prach-FreqOffset-shorterTTI.

<Method 1.1.3>
The ZC sequence in the preamble transmitted by the first user apparatus is different from the ZC sequence in the preamble transmitted by the second user apparatus.

  For example, a first part of the 64 ZC sequences corresponds to the first user apparatus, and a second part of the 64 ZC sequences corresponds to the second user apparatus.

  Specifically, the conventional UE transmits one of 64 ZC sequences as a preamble based on parameters configured by the base station. Except for the non-contention random access sequence, the numberOfRA-Preambles sequence is used by the conventional UE, among which the sizeOfRA-PreamblesGroupA sequence belongs to GroupA, and the rest is GroupB.

  If there is a conventional UE and a short TTI UE in the cell at the same time, the base station adds new parameters to represent the ZC sequences that the short TTI UE can use, and these sequences are It should belong to a part other than the usable sequence.

  For example, the parameter numberOfRA-Preambles-TTItype1 is defined for the first type of short TTI UE, and the sizeOfRA-PreamblesGroupA-TTItype1 is defined; for the second type of short TTI UE, the parameter numberOfRA- Define Preambles-TTItype2 and define the definition sizeOfRA-PreamblesGroupA-TTItype2. Similarly, for more types of short TTI UEs, multiple groups of parameters may be defined to define the range of ZC sequences used.

  Accordingly, the ZC sequences to be used do not overlap each other between the conventional UE and UEs of different types of TTI. For example, the first numberOfRA-Preambles sequence of 64 sequences is used by a conventional UE, and the subsequent numberOfRA-Preambles-TTItype1 sequence is used by a UE of the first type of short TTI, The subsequent numberOfRA-Preambles-TTItype2 sequences are used by the second type of short TTI UE. The previous part of the ZC sequence used by each type of TTI UE is defined to belong to GroupA, and its size (size) is defined by parameters sizeOfRA-PreamblesGroupA-TTItype1, sizeOfRA-PreamblesGroupA-TTItype2, etc. The Further, the latter half of the sequence used by this type of UE belongs to GroupB.

  In another implementation scheme (ie, implementation scheme 1.2), multiple types of TTIs can be distinguished according to the format or content of the preamble.

  Specifically, the conventional UE looks up the preamble format to be used in Table 5.7.1-2 in the TS 36.211 protocol based on the prach-ConfigIndex configured by the base station, which is format0, format1, Includes format2, format3, etc. A new preamble format can be distinguished from conventional UEs by designing it for short TTI UEs. The new format should have a very good cross-correlation with the conventional preamble, and the conventional format and the new format can be transmitted simultaneously with very little interference to each other. Of these, the preamble lengths of the new format and the conventional format do not necessarily have to be the same. The specific design of the new preamble format does not belong to the scope of the present invention, and corresponding random access methods are defined for different formats, taking the characteristics of the three new formats as examples.

<Method 1.2.1>
The length of the preamble adopted by the first user device is different from the length of the preamble adopted by the second user device.

  Among them, the length of the preamble adopted by the first user device is 1 ms, 2 ms, or 3 ms, the length of the preamble adopted by the second user device is 0.5 ms, and the second user device Transmits a preamble by randomly selecting one time slot from a plurality of available time slots.

  Specifically, there is one new format format5 dedicated to short TTI UEs, and the cross-correlation between the existing formats format0, format1, format2, and format3 is very good, and the existing interference is very high. Let it be small. The time length occupied by format5 is 0.5 ms, and the length of cyclic prefix (CP, Cyclic Prefix), guard time (GT, Guard Time), and ZC sequence is not limited.

  FIG. 3 is a diagram showing a preamble having a length different from that of the conventional format in the embodiment of the present invention. As shown in FIG. 3, the time length occupied by format 5 is 0.5 ms. Note that FIG. 3 shows only a new format whose format is different from the conventional preamble format, but the present invention is not limited to this, and may be a format of another length, for example.

  Short TTI UEs all use format5 regardless of what type of format (eg, format0, format1, format2 or format3 is configured) configured by the base station And transmit the preamble. Based on the configuration of the base station, the short TTI UE selects one starting subframe. Based on the situation where the preamble configured by the base station should occupy the number of subframes (ie, acquired time domain resource), one 0.5 ms time slot is randomly selected from multiple types of available time slot resources. Select to send the preamble.

Situation 1: If the format configured by the base station is format 0 (length is 1 ms, ie, 2 time slots), the UE will select from the 2 time slots after the start subframe. Select one time slot at random and transmit;
Situation 2: If format 1 and 2 (length is 2 ms, ie, 4 time slots) configured by the base station, the UE shall have 4 time slots after the start subframe. Randomly select one time slot from within and send;
Situation 3: If the format configured by the base station is format3 (length is 3ms, ie, 6 time slots), the UE shall select from among 6 time slots after the start subframe. One time slot is selected at random and transmitted.

  In this embodiment, the resources used by the UE to transmit the preamble follow the configuration of the base station. The UE records how many timeslots it selects and transmits, and writes s_id (0 <s_id ≦ 6). That is, s_id is a time domain resource that can be selected by a UE with a short TTI. Indicates the position of the time slot for transmitting the preamble. The value of s_id is used for calculation of RA-RNTI described later.

<Method 1.2.2>
The length of the preamble adopted by the first user device and the length of the preamble adopted by the second user device are the same, but the format is different.

  For example, several new formats dedicated to short TTI UEs, format0a (length is 1ms, corresponding to format0), format1a (length is 2ms, corresponding to format1), format2a (length is 2ms) And corresponding to format2), format3a (length is 3ms, corresponding to format3), and the cross-correlation between the corresponding conventional formats format0, format1, format2, format3 is very Good, suppose there is very little interference. The time length occupied by the new format is the same as the corresponding conventional format, and the lengths of the CP, GT, and ZC sequences are not limited.

  FIG. 4 is a diagram showing a preamble having the same length as that of the conventional format in the embodiment of the present invention. As shown in FIG. 4, the time lengths occupied by format0a, format1a, format2a, and format3a are the same as format0, format1, format2, and format3, respectively, but the contents (for example, the lengths of CP, GT, and ZC) Is different.

  The short TTI UE selects a new format corresponding to the preamble format defined in the prach-ConfigIndex parameter configured by the base station. That is, if the conventional UE selects format 0, the short TTI UE selects format 0a, and if the conventional UE selects format 1, the short TTI UE selects format 1a and analogizes based on this be able to. Resources used by the UE to transmit the preamble follow the configuration of the base station. At this time, the UE records s_id = 1, which is used for the calculation of RA-RNTI described later.

<Method 1.2.3>
The ZC sequence in the preamble adopted by the first user device is different from the ZC sequence in the preamble adopted by the second user device, of which the first user corresponds to 64 first ZC sequences. To do. Also, 64 different second ZC sequences are generated for the second user equipment.

  Specifically, based on the rootSequenceIndex parameter configured by a radio resource control (RRC, Radio Resource Control) message, first, 64 sequences are generated for the conventional UE using the root sequence. If less than, according to the order of the root sequence defined in TS 36.211 Table 5.7.2-4, the following one root sequence is used to generate more ZC sequences until reaching 64, and its sequence number index Is 0-63.

  In this implementation method, after the 64 ZC sequences (first ZC sequence) generated for the conventional UE, the 64 ZC sequences (second ZC sequence) is generated for exclusive use by short TTI UEs, and the sequence number (preamble index) is also 0 to 63, which is the same as a conventional UE. That is, the sequence numbers 0 to 63 correspond to one conventional sequence (first ZC sequence) and one new sequence (second ZC sequence). The generated 128 ZC sequences are known to the base station and the UE. Further, the cross-correlation between these 128 ZC sequences is very good.

  The short TTI UE selects the corresponding preamble format based on the base station configuration and uses the same format as the conventional UE, but the transmission sequence is 64 sequences dedicated to the short TTI UE. Is used. Resources used for transmitting the preamble follow the configuration of the base station. At this time, the UE records s_id = 1 in order to calculate RA-RNTI described later.

  In this embodiment, grouping of ZC sequences may be further performed for a UE with a short TTI, and this can be applied to all implementation schemes other than the above-described implementation scheme 1.1.3 of the present invention. . A short TTI UE has 64 ZCs when it can distinguish between conventional UEs and short TTI UEs in two ways: time frequency resources and preamble format (independent of grouping ZC sequences). You can occupy a sequence. Grouping for short TTI UEs does not affect grouping for conventional UEs, and they are independent of each other.

  These 64 sequences occupied by short TTI UEs need to be used for short TTI UEs of different lengths. Here, it is assumed that a sequence based on non-contention is shared by a conventional UE and a short TTI UE. By grouping, GroupA and GroupB sequences of each type are distinguished for UEs having different TTI types (for example, 0.5 ms, 0.1 ms, etc.).

  For example, parameters numberOfRA-Preambles-TTItype1 and sizeOfRA-PreamblesGroupA-TTItype1 are defined for short TTI type 1 UEs, and parameters numberOfRA-Preambles-TTItype2 and sizeOfRA-PreamblesGroupA-TTItype2 are defined for short TTI type 2 UEs. And, based on this, define parameters for each type of specific short TTI type, thereby limiting the range of sequences that can be used by that type of UE. Among them, numberOfRA-Preambles-TTItypei indicates the number of ZC sequences that can be used by the i-th type short TTI UE, and sizeOfRA-PreamblesGroupA-TTItypei is the sequence that can be used by the i-type short TTI UE. Indicates the number of sequences belonging to Group A, and the remaining sequences belong to Group B.

  FIG. 5 is a diagram illustrating grouping for 64 sequences occupied by a UE having a short TTI according to an embodiment of the present invention. As shown in FIG. 5, the first type of short TTI UE can use a sequence numbered from 0 to numberOfRA-Preambles-TTItype1-1, of which the previous sizeOfRA-PreamblesGroupA-TTItype1 Sequences belong to Group A, the remaining sequences belong to Group B, and the second type of short TTI UEs have a sequence number from numberOfRA-Preambles-TTItype1 to numberOfRA-Preambles-TTItype1 + numberOfRA-Preambles-TTItype2-1 The previous sequence of sizeOfRA-PreamblesGroupA-TTItype2 belongs to GroupA, and the rest is GroupB, and can be inferred based on this.

  In the present embodiment, the user apparatus may further transmit a first message not indicating the TTI type when the transmission of the first message indicating the TTI type fails.

  For example, when a short TTI UE transmits a preamble according to the above-described method and notifies the base station of the TTI type, if all of the multiple attempts fail, the short TTI UE transmits the conventional UE transmission method. The preamble should be transmitted according to Relevant TTI type information may be carried by subsequent signaling (eg, carry TTI type information in message 3), and during this period, transmission is performed using conventional TTI.

  Although step 101 or 201 has been described above as an example, step 102 or 202 will be described below.

  In this embodiment, the user equipment monitors the physical downlink control channel (PDCCH, Physical Downlink Control Channel) scrambled by RA-RNTI when the three TTIs after transmitting the preamble are completed. Begin to.

  For example, after transmitting the preamble, the UE monitors the PDCCH scrambled by the RA-RNTI within the “RAR time window” and receives the RAR corresponding to its own RA-RNTI. If the RAR transmitted by the base station cannot be received within this RAR time window, it means that the current random access procedure has failed.

  For conventional UEs, the RAR time window is from (starts) three subframes after the subframe transmitting the preamble. For short TTI UEs, the RAR time window is from 3 TTIs after transmitting the preamble (eg, for 0.5 ms TTIs, it may start receiving RAR after 1.5 ms), and , Lasts for the length of ra-ResponseWindowSize TTIs.

  In the implementation scheme 1.1, both the first user apparatus and the second user apparatus can support the first RA-RNTI (ie, the conventional RA-RNTI). In an implementation scheme 1.2, the first user apparatus corresponds to a first RA-RNTI, and the first RA-RNTI is determined by a time domain resource and a frequency domain resource that transmit the preamble, and the second user apparatus Corresponds to a second RA-RNTI different from the first RA-RNTI.

  For example, the conventional method of calculating the RA-RNTI by the UE is RA-RNTI = 1 + t_id + 10 * f_id, where t_id is the first random access channel resource selected by the UE to transmit the preamble. The sub-frame order number (0 ≦ t_id <10), and f_id is the frequency domain (0 ≦ f_id <6) of the random access channel selected by the UE to transmit the preamble. RA-RNTI is used to distinguish RARs corresponding to UEs that transmit preambles using different time frequency resources.

  In this embodiment, when a conventional UE and a short TTI UE use the same preamble resource, and the same ZC sequence or the same ZC sequence sequence number (for example 1.2.3, the sequence number index is 64 at maximum). However, RA-RNTI can distinguish RARs corresponding to conventional UEs and short TTI UEs when 128 ZC sequences are available.

  Therefore, the embodiment of the present invention defines one new RA-RNTI calculation method for short TTI UEs. The RA-RNTI corresponding to a UE with a short TTI may not only relate to time domain resources and frequency domain resources that transmit the preamble, but may also relate to a time slot position that transmits the preamble.

  In the present embodiment, the value of the second RA-RNTI may be a value obtained by adding a positive integer multiple of 60 to the value of the first RA-RNTI.

  For example, a short TTI UE adopts the following method to calculate RA-RNTI, that is, RA-RNTI = 1 + t_id + 10 * f_id + 60 * s_id. Among them, the default value of s_id is 1, and as described above, s_id indicates a time slot position for transmitting a preamble in a time domain resource that can be selected by a UE with a short TTI. Note that the conventional RA-RNTI calculation formula may be regarded as a special case when s_id = 0.

  Although the RA-RNTI calculation method has been exemplarily described above, the present invention is not limited to this. You may adjust suitably about the above-mentioned calculation formula according to an actual condition. The numerical ranges of the new RA-RNTI and the conventional RA-RNTI may be made different as long as no common set exists.

  In the present embodiment, the base station can know the TTI type of the UE that transmits the preamble from the message 1, or the base station can grasp the TTI type of the UE by another method such as a core network. Yes, the base station should transmit the corresponding RAR for different types of UEs. For example, the base station scrambles the PDCCH using the first RA-RNTI for the RAR of the first user apparatus, and uses the second RA-RNTI to the PDCCH for the RAR of the second user apparatus. Scrambling is performed. Each user apparatus may descramble the PDCCH based on its own RA-RNTI. Note that the present invention is not limited to this, and the base station may scramble each user apparatus using the first RA-RNTI. Refer to Embodiment 2 for specific contents. be able to.

  In addition, there is a possibility that the base station does not know the TTI type of the UE that transmits the preamble. In such a case, the base station receives a plurality of RARs corresponding to the plurality of types of TTIs for one received preamble. You may send it. For example, for each detected preamble, two RARs are transmitted (for a conventional UE and a 0.5 ms TTI UE, respectively).

  The user equipment can obtain RAR in the following manner. The first user device descrambles the PDCCH using the first RA-RNTI, the second user device descrambles the PDCCH using the second RA-RNTI, and further the PDCCH Decoding may be performed on a physical downlink shared channel (PDSCH) based on the instruction.

  For example, when the base station transmits two RARs for one received preamble, the UE can accurately receive the RAR corresponding to the UE in the following two types.

  Method 1: A conventional UE adopts a conventional RA-RNTI calculation method, and a short TTI UE adopts a RA-RNTI calculation method newly defined in the present invention. The base station scrambles RARs using different RA-RNTIs. When the UE descrambles the PDCCH using RA-RNTI, the UE can distinguish between the RAR of the conventional UE and the RAR of the short TTI UE.

  Scheme 2: The UE receives all RARs within the RAR time window and decrypts the PDSCH channel according to its TTI type. If the sent RAR is not a RAR corresponding to your TTI type, it means that there is an error in the data, discard the RAR, otherwise the RAR corresponds to your TTI type Is considered.

  In step 103 and step 104, the following operation may be performed.

  The user apparatus transmits the third message to the base station when the six TTIs after receiving the RAR are completed. For example, the conventional UE can transmit message 3 (Msg3) in the sixth subframe after receiving the RAR, but the UE with a short TTI receives the sixth one after receiving the RAR. Message 3 should be sent after the TTI of the eye.

  Once the message 3 is sent, the UE should start one contention resolution timer mac-ContentionResolutionTimer, the value of which is configured by the base station. For conventional UEs, the unit of the timer value is a subframe, but for a short TTI UE, the unit of the timer value is TTI (0.5 ms or shorter).

  Since the subsequent operation of the random access procedure is similar to the conventional random access procedure, detailed description thereof is omitted here.

  As can be seen from the above-mentioned embodiment, the base station distinguishes which type of TTI the user equipment transmits the preamble by instructing the TTI type of the user equipment using the first message for transmitting the preamble. In addition, since the user apparatus can also distinguish the received RAR, the ambiguity and error of RAR reception are not caused. Thereby, the latency of the random access procedure of the user apparatus with a short TTI can be significantly reduced.

  Embodiments of the present invention provide a random access method that supports multiple types of TTI, which is used in a base station. The content of the embodiment of the present invention that is the same as that of Embodiment 1 is omitted.

  FIG. 6 is a diagram showing a random access method that supports a plurality of types of TTIs in the embodiment of the present invention, and shows the situation on the base station side. As shown in FIG. 6, the random access method includes the following steps.

Step 601: The base station receives the preamble for requesting random access transmitted from the user equipment by the first message, and the TTI type of the user equipment is indicated by the first message. ;
Step 602: The base station transmits a RAR to the user equipment by a second message, wherein different TTI types correspond to different RARs.

  In this embodiment, it may be a contention based random access procedure, and the random access method further includes: the base station receives a user equipment identifier transmitted using a third message by the user equipment; and The base station may include transmitting contention result information to the user equipment using a fourth message. Note that the present invention is not limited to this, and can be applied to other types of random access procedures.

  In the present embodiment, the base station detects a preamble that can exist on the configured time frequency resource position, and performs a response, that is, RAR, on the detected preamble. Among them, the base station can transmit the RAR to the user apparatus on the PDCCH scrambled by the RA-RNTI when the three TTIs after receiving the preamble are completed.

  In this embodiment, the user device may include a first user device using a first TTI type and a second user device using a second TTI type, of which the first TTI type and the second TTI type are included. TTI corresponding to the type is different and is 1 ms or less.

  In the case of the implementation scheme 1.1 described above, both the first user device and the second user device can support conventional RNTI (ie, first RA-RNTI). In the case of the implementation scheme 1.2 described above, the first user apparatus can support a first RA-RNTI, and the first RA-RNTI is determined by a time domain resource and a frequency domain resource that transmit the preamble. The second user apparatus can support a second RA-RNTI different from the first RA-RNTI. Example 1 can be referred to for specific implementation of the above contents.

  Hereinafter, related operations of the base station will be described by dividing the two cases.

<Method 2.1>
The base station is different if the base station knows the TTI type of the UE that transmits the preamble from the message 1 or the base station can grasp the TTI type of the UE by another method such as a core network. The corresponding RAR should be sent to the type of UE.

[In the case of implementation method 1.1]
Since the base station knows the status of the grouping of the configured time frequency resource and ZC sequence, it determines the UE type corresponding to the preamble based on the position of the time frequency resource that detected the preamble and the ZC sequence Different RARs can then be sent. At this time, a conventional RA-RNTI (ie, first RA-RNTI) calculation method is employed.

[In the case of implementation method 1.2]
For implementation scheme 1.2.1, the base station first detects the conventional preamble format and then detects the format format5, thereby detecting the possible preambles from the conventional UE and the short TTI UE, respectively. , And send different RARs. At this time, the RA-RNTI (that is, the second RA-RNTI) calculation method newly defined in the present invention is adopted.

  For implementation scheme 1.2.2 and implementation scheme 1.2.3, the base station employs detection of conventional preamble format to simultaneously detect possible preambles from conventional UE and short TTI UE, and different RARs Can be sent. At this time, the RA-RNTI (that is, the second RA-RNTI) calculation method newly defined in the present invention is adopted.

  The base station can transmit the RAR after 3 TTIs to the detected UE after detecting the preamble (3 ms for conventional UEs and less time for UEs with short TTIs). is there).

  In the present embodiment, a random access preamble identifier (RAPID) field in the RAR indicates a ZC sequence order number, the value is 0 to 63, and the new 64 ZC sequences are the conventional ones. Share the 64 sequence numbers with the 64 ZC sequences. The uplink grant (UL Grant, Uplink Grant) field is the resource location scheduled for the UE, and the UL Grant in the RAR transmitted to the short TTI UE is scheduled according to the short TTI. The backoff indicator (BI) field indicates the backoff time of the UE, and should be configured to be relatively small for a short TTI UE.

<Method 2.2>
If the base station cannot know the TTI type of the UE transmitting the preamble by using message 1, the base station detects two RARs for each detected preamble (for the conventional UE and the 0.5 ms TTI UE, respectively). Can be sent). Note that the present invention is not limited to this, and for example, more RARs may be transmitted.

  The base station may share some (or all) time frequency resources and ZC sequence resources with conventional UEs and short TTI UEs. After detecting the preamble on such a resource, the base station considers that there may be a conventional UE and a short TTI UE transmitting the preamble at the same time. The base station assigns UL grants for conventional UEs and short TTI UEs at the same time, one of which resources may be wasted.

  For example, when the base station transmits two RARs for one received preamble, the UE can accurately receive the RAR corresponding to the UE in the following two types.

  Method 1: Conventional UE adopts conventional RA-RNTI (first RA-RNTI) calculation method, and short TTI UE newly defines RA-RNTI (second RA-RNTI) calculation in the present invention. Adopt the method. Each base station scrambles RARs using different RA-RNTIs. When descrambling the PDCCH using the RA-RNTI, the UE can distinguish the RAR of the conventional UE and the RAR of the short TTI UE.

  Scheme 2: The UE receives all RARs within the RAR time window and decodes (decodes) the PDSCH channel based on its own TTI type. If the sent RAR is not a RAR corresponding to your TTI type, it means that there is an error in the data, discard the RAR, otherwise the RAR corresponds to your TTI type Is considered.

  As can be seen from the above-mentioned embodiment, the base station distinguishes which type of TTI the user equipment transmits the preamble by instructing the TTI type of the user equipment using the first message for transmitting the preamble. And the user equipment can distinguish the received RAR, and therefore does not cause ambiguity or error in RAR reception. Thereby, the latency of the random access procedure of the user apparatus with a short TTI can be significantly reduced.

  Embodiments of the present invention provide a random access device that supports multiple types of TTI, which is configured in a user equipment. Since the embodiment of the present invention corresponds to the random access method of Embodiment 1, the same contents are omitted.

  FIG. 7 is a diagram illustrating a random access apparatus that supports a plurality of types of TTIs according to an embodiment of the present invention. As shown in FIG. 7, the random access device 700 includes the following.

Random request transmission unit 701: transmits a preamble for requesting random access to the base station by a first message, of which the TTI type of the user equipment is indicated by the first message;
Random response receiving unit 702: Receives RAR transmitted by the base station using a second message, and different TTI types correspond to different RARs.

  FIG. 8 is another diagram illustrating a random access apparatus that supports a plurality of types of TTIs according to an embodiment of the present invention. As shown in FIG. 8, the random access device 800 includes a random request transmission unit 701 and a random response reception unit 702 as described above.

  Further, as shown in FIG. 8, the random access device 800 may further include the following.

Identifier sending unit 801: sending a user equipment identifier to the base station for contention by means of a third message;
Result receiving unit 802: receives contention result information transmitted by the base station using a fourth message.

  In the present embodiment, the user device includes a first user device that uses the first TTI type and a second user device that uses the second TTI type, and includes the first TTI type and the second TTI type. The corresponding TTI is different and is less than 1 ms.

  In one implementation, a plurality of TTI types are distinguished by resources occupied by the preamble, and the resources include one or any combination of time domain resources, frequency domain resources, and sequence resources.

  For example, the time domain resource of the preamble transmitted by the first user apparatus and the time domain resource of the preamble transmitted by the second user apparatus are different and orthogonal to each other. Among them, the first user device uses a first time domain resource table, and the second user device uses a second time domain resource table, and the first time domain resource table and the second time domain resource table. In the table, the same physical random access channel configuration index corresponds to different subframe order numbers.

  For example, the frequency domain resource of the preamble transmitted by the first user apparatus and the frequency domain resource of the preamble transmitted by the second user apparatus are different and orthogonal to each other. Among them, the first user apparatus uses a first parameter to select a frequency domain resource to transmit the preamble, and the second user apparatus uses a second parameter to transmit the preamble. Select a region resource.

  Further, for example, the ZC sequence in the preamble transmitted by the first user apparatus is different from the ZC sequence in the preamble transmitted by the second user apparatus, and among them, the first part in 64 ZC sequences Corresponds to the first user device, and the second part in the 64 ZC sequences corresponds to the second user device.

  In another implementation, a plurality of TTI types are distinguished according to the format or content of the preamble.

  For example, the length of the preamble adopted by the first user device is different from the length of the preamble adopted by the second user device, and the length of the preamble adopted by the first user device is 1 ms, 2 ms. Or the length of the preamble adopted by the second user apparatus is 0.5 ms, and the second user apparatus randomly selects one time slot from a plurality of usable time slots. To transmit the preamble.

  Also, for example, the length of the preamble adopted by the first user device is the same as the length of the preamble adopted by the second user device, but the format is different.

  Further, for example, the ZC sequence in the preamble adopted by the first user device is different from the ZC sequence in the preamble adopted by the second user device, and the first user device has 64 first Corresponds to one ZC sequence. Also, 64 different second ZC sequences are generated for the second user device.

  In the present embodiment, the random request transmission unit 701 may further transmit a first message not indicating the TTI type when the transmission of the first message indicating the TTI type fails.

  In this embodiment, the random response receiving unit 702 starts monitoring the PDCCH scrambled by the RA-RNTI when the three TTIs after the random request transmitting unit 701 transmits the preamble are completed.

  The identifier transmission unit 801 transmits the third message to the base station when six TTIs after receiving the random access response are completed.

  In the present embodiment, in the case of the implementation method 1.1 described above, both the first user device and the second user device can correspond to the first RA-RNTI. Both the first user apparatus and the second user apparatus can descramble the PDCCH using the first RA-RNTI.

  In the case of the implementation scheme 1.2 described above, the first user apparatus can support a first RA-RNTI, and the first RA-RNTI is determined by a time domain resource and a frequency domain resource that transmit the preamble. The second user apparatus can support a second RA-RNTI different from the first RA-RNTI. The first user equipment can descramble the PDCCH using the first RA-RNTI, and the second user equipment descrambles the PDCCH using the second RA-RNTI. It can be performed. Further, the PDSCH may be decoded based on the PDCCH instruction.

  The embodiments of the present invention further provide a user device, in which a random access device 700 or 800 as described above is configured.

  FIG. 9 is a diagram illustrating a user apparatus according to an embodiment of the present invention. As shown in FIG. 9, the user device 900 includes a central processing unit 100 and a storage unit 140, and the storage unit 140 is connected to the central processing unit 100. The figure is merely an example, and the structure may be supplemented or replaced with another type of structure to realize a telecommunication function or another function.

  In one implementation, the functions of the random access device 700 or 800 may be integrated into the central processing unit 100. Among them, the central processing unit 100 may be configured to realize a random access method that supports a plurality of types of TTIs as described in the first embodiment.

  In another implementation, the random access device 700 or 800 may be configured separately from the central processing unit 100. For example, the random access device 700 or 800 is configured as a chip connected to the central processing unit 100. The functions of the random access device 700 or 800 may be realized by the control of the central processing unit.

  As shown in FIG. 9, the user device 900 may further include a communication module 110, an input unit 120, an audio processor 130, a storage device 140, a camera 150, a display 160, and a power source 170. Among these, the functions of these components are similar to those of the prior art, and thus detailed description thereof is omitted here. Note that the user device 900 does not necessarily include all the components in FIG. Further, the user device 900 may further include those not shown in FIG. 9, and for this, reference can be made to the prior art.

  As can be seen from the above-mentioned embodiment, the base station distinguishes which type of TTI the user equipment transmits the preamble by instructing the TTI type of the user equipment using the first message for transmitting the preamble. In addition, since the user apparatus can distinguish the received RAR, there is no ambiguity or error in RAR reception. Thereby, the latency of the random access procedure of the user equipment of TTI can be significantly reduced.

  Embodiments of the present invention provide a random access device that supports multiple types of TTI, which is configured in a base station. The embodiment of the present invention corresponds to the random access method of Embodiment 2, and the same contents are omitted.

  FIG. 10 is a diagram illustrating a random access apparatus that supports a plurality of types of TTIs according to an embodiment of the present invention. As shown in FIG. 10, the random access device 1000 includes the following.

Random request receiving unit 1001: The first message receives a preamble for requesting random access transmitted by the user device, and the first message indicates the TTI type of the user device;
Random response transmission unit 1002: Sends a RAR to the user equipment by a second message, of which different TTI types correspond to different RARs.

  FIG. 11 is another diagram illustrating a random access apparatus that supports a plurality of types of TTIs according to an embodiment of the present invention. As shown in FIG. 11, the random access device 1100 includes a random request receiving unit 1001 and a random response transmitting unit 1002 as described above.

  Further, as shown in FIG. 11, the random access device 1100 may further include the following.

Identifier receiving unit 1101: Receives a user device identifier sent by the user device by a third message; and Result sending unit 1102: Sends contention result information to the user device by a fourth message.

  In this embodiment, the random response transmission unit 1002 uses the PDCCH scrambled by the RA-RNTI when the three TTIs after the random request reception unit 1001 receives the preamble ends. , To the user device.

  In this embodiment, the user device may include a first user device using a first TTI type and a second user device using a second TTI type, of which the first TTI type and the second TTI type The corresponding TTI is different and is less than 1 ms.

  In the present embodiment, in the case of the implementation method 1.1 described above, both the first user device and the second user device can correspond to the first RA-RNTI. In the case of the implementation scheme 1.2 described above, the first user apparatus can support a first RA-RNTI, and the first RA-RNTI is determined by a time domain resource and a frequency domain resource that transmit the preamble. The second user apparatus can support a second RA-RNTI different from the first RA-RNTI.

  In this embodiment, the random response transmission unit 1002 can further transmit a plurality of RARs corresponding to the plurality of types of TTIs with respect to one received preamble.

  The embodiment of the present invention further provides a base station, in which a random access device 1000 or 1100 as described above is configured.

  FIG. 12 is a block diagram of the base station in the embodiment of the present invention. As shown in FIG. 12, the base station 1200 may include a central processing unit (CPU) 200 and a storage unit 210, and the storage unit 210 is connected to the central processing unit 200. Among them, the storage device 210 can store various types of data, can further store a program for information processing, and can execute the program under the control of the central processing unit 200. it can.

  Among them, the functions of the random access device 1000 or 1100 can be integrated into the central processing unit 200. The central processing unit 200 may be configured to implement a random access method that supports a plurality of types of TTIs as described in the second embodiment.

  Also, as shown in FIG. 12, the base station 1200 may further include a transceiver 220, an antenna 230, etc., of which the functions of these components are similar to those of the prior art, and a detailed description thereof will be given here. Omitted. Note that the base station 1200 does not necessarily need to include all of those shown in FIG. Further, the base station 1200 may further include those not shown in FIG. 12, but the prior art can be referred to for this.

  As can be seen from the above-described embodiment, by using the first message for transmitting the preamble to indicate the TTI type of the user apparatus, the base station can determine which type of TTI type user apparatus the preamble is transmitted to. Since the user apparatus can distinguish the received RAR, the ambiguity and error of the RAR reception are not caused. Thereby, the latency of the random access procedure of the user apparatus with a short TTI can be significantly reduced.

  Embodiments of the present invention further provide a communication system, which can support multiple types of TTIs. In addition, the content which is the same as Examples 1-4 of the Example of this invention is abbreviate | omitted.

  FIG. 13 is a diagram showing a communication system in an embodiment of the present invention. As shown in FIG. 13, the communication system 1300 includes a base station 1301 and a user equipment 1302.

  Among them, the user apparatus 1302 transmits a preamble for requesting random access by a first message, and among them, the TTI type of the user apparatus 1302 is indicated by the first message, and the base station 1301 The base station 1301 transmits the RAR to the user apparatus 1302 by a second message, the base station 1301 receives the preamble transmitted by the user apparatus 1302 by a first message, and different TTI types are transmitted to different RARs. Correspondingly, the user device 1302 receives the RAR transmitted by the second message.

  An embodiment of the present invention provides a computer-readable program, and when the program is executed in a user device, the program is stored in the user device at a plurality of types of TTIs described in the first embodiment. Run a random access method that supports.

  An embodiment of the present invention provides a storage medium storing a computer readable program, wherein the computer readable program supports a plurality of types of TTIs described in the first embodiment in a user device in a computer. Is executed.

  An embodiment of the present invention provides a computer readable program, of which when the program is executed in a base station, the program is stored in the base station in the plurality of types of TTIs described in the second embodiment. Run a random access method that supports.

  An embodiment of the present invention provides a storage medium storing a computer-readable program, wherein the computer-readable program allows a computer to support a plurality of types of TTIs described in the second embodiment in a base station. Is executed.

  The above apparatus and method of the present invention may be realized by software or hardware, or may be realized by a combination of hardware and software. The present invention further relates to a computer readable program as follows: when the program is executed by a logic component, the logic component realizes the above-described apparatus or structural component, or the logic component. The above-described various methods or steps are realized. The logic component may be, for example, an FPGA (Field Programmable Gate Array), a microprocessor, or a processor used in a computer. The present invention further relates to a storage medium storing the above-described program, for example, a hard disk, a magnetic disk, an optical hard disk, a DVD, a flash memory, and the like.

  In addition, one or more of the functional blocks described in the drawings and / or one or more combinations of the functional blocks are a general-purpose processing device or digital signal processing device for executing the function described in the present invention. (DSP), dedicated integrated circuit (ASIC), FPGA (field-programmable gate array) or other programmable logic elements, logic gate or transistor logic elements, hardware assembly or any other suitable combination . In addition, one or more of the functional blocks described in the drawings and / or one or more combinations of the functional blocks may be a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, It may be implemented as one or more microprocessors or any other configuration communicatively connected to the DSP.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to such embodiment, As long as it does not remove | deviate from the meaning of this invention, all the changes with respect to this invention belong to the technical scope of this invention.

Claims (10)

A terminal device that supports a plurality of transmission time intervals and can execute a random access procedure,
A transmission unit that transmits a first message of the random access procedure including a preamble to a base station using one transmission time interval of the plurality of types of transmission time intervals;
Receiving a second message of the random access procedure from the base station that has received the first message,
The terminal device characterized in that the identification information used in the random access procedure corresponds to information indicating a position of a slot for transmitting the preamble.   The terminal apparatus according to claim 1, wherein the identification information is a random access radio network temporary identifier (RA-RNTI).   The reception unit starts monitoring a physical downlink control channel scrambled by the random access wireless network temporary identifier when a predetermined period after the preamble is transmitted elapses. Terminal equipment.   The terminal apparatus according to any one of claims 1 to 3, wherein the identification information corresponds to information indicating a position of a slot for transmitting the preamble and information on a frequency domain. The transmitter, after receiving the second message, transmits a third message of the random access procedure including the identifier of the terminal device,
5. The terminal device according to claim 1, wherein the reception unit receives a fourth message of the random access procedure transmitted from a base station according to the third message. 6. .   The plurality of types of transmission time intervals include a first type of transmission time interval and a second type of transmission time interval, and the first type of transmission time interval and the second type of transmission time interval are 1 ms or less. The terminal device according to any one of claims 1 to 5, wherein   The terminal apparatus according to claim 1, wherein the transmission time interval corresponds to a length of the preamble. A base station that supports multiple types of transmission time intervals and is capable of performing random access procedures,
A receiving unit for receiving a first message of the random access procedure including a preamble transmitted from a terminal device using one of the plurality of types of transmission time intervals;
A transmission unit that transmits a second message of the random access procedure to the terminal in response to the first message,
The base station characterized in that the identification information used in the random access procedure corresponds to information indicating a position of a slot for transmitting the preamble.   The base station according to claim 8, wherein the transmission unit transmits the physical downlink control channel scrambled according to the identification information and the second message. A communication method of a terminal device that supports a plurality of transmission time intervals and can execute a random access procedure,
A first message of the random access procedure including a preamble is transmitted to a base station using one transmission time interval of the plurality of types of transmission time intervals;
Receiving a second message of the random access procedure from a base station that has received the first message;
The terminal device communication method according to claim 1, wherein the identification information used in the random access procedure corresponds to information indicating a position of a slot for transmitting the preamble.